练习2：投资翻倍计算 8.7
Python
money = 10000 # 初始本金
target = money * 2 # 目标金额
years = 0 # 年数
while money < target:
money = money * 1.05 # 每年增长5%
years = years + 1
print(f"第{years}年，资产为：{money:.2f}元")
print(f"需要{years}年资产可以翻倍。")
